Premium device-aided low-tier device group delay calibration for nr positioning

ABSTRACT

Techniques are provided for calibrating group delay for a low-tier UE by leveraging the relatively high accuracy of RTT positioning for a premium UE. This can enable online/in-field group delay calibration of low-tier UEs, allowing for low-tier UEs to be calibrated when needed. Depending on desired functionality, techniques for calibration may include the use of RTT measurements with a base station, or an RTT measurement between the low-tier UE and the premium UE.

BACKGROUND

Determining the location of a mobile electronic device (also referred toherein as a User Equipment (UE)) using a cellular network may usesignaling between the device and base stations of the cellular network.According to some techniques, Round-Trip-Time (RTT) measurements may bemade to determine distances between the device and the base stations,from which the location of the device may be determined. But thesemeasurements can suffer inaccuracy due to internal delays at the device.

BRIEF SUMMARY

Techniques described herein provide for calibrating group delay for alow-tier device by leveraging the relatively high accuracy of RTTpositioning for a premium device. This can enable in-field group delaycalibration of low-tier devices, allowing for low-tier devices to becalibrated when needed. Depending on desired functionality, techniquesfor calibration may include the use of RTT measurements with a basestation, or an RTT measurement between the low-tier device and thepremium device.

An example method of determining a group delay of a first mobile device,according to this description, comprises obtaining a first RTTmeasurement between the first mobile device and a base station, andidentifying a second mobile device within a threshold distance of thefirst mobile device, wherein the second mobile device has a higherbandwidth than the first mobile device. The method further includesobtaining a second RTT measurement between the second mobile device andthe base station, and determining a group delay of the first mobiledevice based on a difference between the first RTT measurement and thesecond RTT measurement.

Another example method of determining a group delay of a first mobiledevice, according to this description, comprises obtaining informationindicative of a known distance between the first mobile device and asecond mobile device, wherein the second mobile device has a higherbandwidth than the first mobile device and obtaining an RTT measurementbetween the first mobile device and the second mobile device. The methodfurther includes determining a group delay of the first mobile devicebased on a difference between the known distance and a distancedetermined by the RTT measurement.

An example device, according to this description, comprises atransceiver, a memory, and one or more processing units communicativelycoupled with the transceiver and the memory. The one or more processingunits are configured to obtain a first RTT measurement between a firstmobile device and a base station, and identify a second mobile devicewithin a threshold distance of the first mobile device, wherein thesecond mobile device has a higher bandwidth than the first mobiledevice. The one or more processing units are also configured to obtain asecond RTT measurement between the second mobile device and the basestation, and determine a group delay of the first mobile device based ona difference between the first RTT measurement and the second RTTmeasurement.

An example mobile device, according to this description, comprises atransceiver, a memory, and one or more processing units communicativelycoupled with the transceiver and the memory. The one or more processingunits are configured to obtain information indicative of a knowndistance between a first mobile device and a second mobile device,wherein the second mobile device has a higher bandwidth than the firstmobile device. The one or more processing units are also configured toobtain, using the transceiver, an RTT measurement between the firstmobile device and the second mobile device, and determine a group delayof the first mobile device based on a difference between the knowndistance and a distance determined by the RTT measurement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a terrestrial positioning system, according to anembodiment.

FIG. 2 is a timing diagram illustrating the basic steps of an RTTmeasurement, according to an embodiment.

FIG. 3 is a timing diagram illustrating how group delay can impact theaccuracy of RTT measurements.

FIG. 4 is a diagram of a first technique for group delay calibration ofa low-tier device, according to an embodiment.

FIG. 5 is a diagram of a second technique for group delay calibration ofa low-tier device, according to an embodiment.

FIG. 6 is a flow diagram of a method of determining the group delay of afirst device (e.g., a low-tier device), according to an embodimentutilizing a base station.

FIG. 7 is a flow diagram of a method of determining the group delay of afirst device (e.g., a low-tier device), according to an embodiment thatuses direct communications with a second device (e.g., a premiumdevice).

FIG. 8 is block diagram of an embodiment of a device.

FIG. 9 is block diagram of an embodiment of a base station.

Like reference symbols in the various drawings indicate like elements,in accordance with certain example implementations. In addition,multiple instances of an element may be indicated by following a firstnumber for the element with a letter or a hyphen and a second number.For example, multiple instances of an element 110 may be indicated as110-1, 110-2, 110-3, etc. or as 110 a, 110 b, 110 c, etc. When referringto such an element using only the first number, any instance of theelement is to be understood (e.g., element 110 in the previous examplewould refer to elements 110-1, 110-2, and 110-3 or to elements 110 a,110 b, and 110 c).

DETAILED DESCRIPTION

Several illustrative embodiments will now be described with respect tothe accompanying drawings, which form a part hereof. While particularembodiments, in which one or more aspects of the disclosure may beimplemented, are described below, other embodiments may be used andvarious modifications may be made without departing from the scope ofthe disclosure or the spirit of the appended claims.

Fifth-Generation (5G) New Radio (NR) is a wireless radio frequency (RF)interface undergoing standardization by the 3rd Generation PartnershipProject (3GPP). 5G NR is poised to offer enhanced functionality overprevious generation (Long-Term Evolution (LTE)) technologies, such assignificantly faster and more responsive mobile broadband, enhancedconductivity through Internet of Things (IoT) devices, and more.Additionally, 5G NR enables new positioning techniques for UEs,including Angle of Arrival (AoA)/Angle of Departure (AoD) positioning,UE-based positioning, and multi-cell RTT positioning. With regard to RTTpositioning, this involves taking RTT measurements between the UE andmultiple base stations.

FIG. 1 is a diagram of a terrestrial positioning system 100, accordingto an embodiment. Here, the terrestrial positioning system comprisesmultiple cellular transceivers, or base stations 110-1, 110-2, and 110-3(generically and collectively referred to herein as base stations 110),which are used to determine the location (e.g., in geographicalcoordinates) of a UE 120. The base stations 110 and/or the UE 120 bothmay be communicatively coupled with a location server 130 via a WideArea Network (WAN) 140, which may comprise a network of the cellularcarrier, as well as other data communication networks, as discussed inmore detail below. (Solid arrows between components indicatecommunication links.) Although the UE 120 may be communicatively coupledwith the WAN 140 via wireless communication with one or more of the basestations 110, the UE 120 may have an additional or alternativecommunication link to the WAN 140, as illustrated.

It should be noted that FIG. 1 provides a generalized illustration ofvarious components, any or all of which may be utilized as appropriate,and each of which may be duplicated or omitted as necessary.Specifically, although one UE 120 is illustrated, it will be understoodthat many UEs (e.g., hundreds, thousands, millions, etc.) may utilizethe terrestrial positioning system 100. Similarly, the terrestrialpositioning system 100 may include a larger or smaller number of basestations 110, location servers 130, and/or other components. Theillustrated communication links that communicatively connect the variouscomponents in the terrestrial positioning system 100 include data andsignaling connections, which may include additional (intermediary)components, direct or indirect physical (wired) and/or wirelessconnections, and/or additional networks. Furthermore, components may berearranged, combined, separated, substituted, and/or omitted, dependingon desired functionality.

The UE 120, as used herein, may be an electronic device and may bereferred to as a device, a mobile device, a wireless device, a mobileterminal, a terminal, a wireless terminal, a mobile station (MS), aSecure User Plane Location (SUPL)-Enabled Terminal (SET), or as someother name. Moreover, UE 120 may correspond to a cellphone, smartphone,laptop, tablet, personal data assistant (PDA), wearable device (e.g.,smart watch), tracking device, or some other portable or moveabledevice. In some cases, a UE 120 may be part of some other entity, forexample, may be a chipset supporting a modem that is integrated intosome larger mobile entity such as a vehicle, drone, package, shipment,or robotic device. Typically, though not necessarily, the UE 120 maysupport wireless communication using one or more Radio AccessTechnologies (RATs) (e.g., in addition to 5G NR), such as Global Systemfor Mobile communication (GSM), Code Division Multiple Access (CDMA),Wideband CDMA (WCDMA), LTE, High Rate Packet Data (HRPD), IEEE 802.11Wi-Fi, Bluetooth® (BT), Worldwide Interoperability for Microwave Access(WiMAX), etc. The UE 120 may also support wireless communication using aWireless Local Area Network (WLAN) which may connect to other networks(e.g. the Internet) using a Digital Subscriber Line (DSL) or packetcable, for example. The WAN 140 may comprise such wireless communicationnetworks and/or technologies.

The UE 120 may include a single entity or may include multiple entitiessuch as in a personal area network where a user may employ audio, video,and/or data input/output (I/O) devices and/or body sensors and aseparate wireline or wireless modem. An estimate of a location of the UE120 may be referred to as a location, location estimate, location fix,fix, position, position estimate, or position fix, and may be geodetic,thus providing location coordinates for the UE 120 (i.e., latitude andlongitude) which may or may not include an altitude component (e.g.,height above sea level, height above or depth below ground level, floorlevel or basement level). Alternatively, a location of the UE 120 may beexpressed as a civic location (e.g., as a postal address or thedesignation of some point or small area in a building such as aparticular room or floor). A location of the UE 120 may also beexpressed as an area or volume (defined either geodetically or in civicform) within which the UE 120 is expected to be located with someprobability or confidence level (e.g., 67%, 95%, etc.). A location ofthe UE 120 may further be a relative location comprising, for example, adistance and direction or relative X and Y (and, optionally, Z)coordinates defined relative to some origin at a known location whichmay be defined geodetically, in civic terms, or by reference to a point,area, or volume indicated on a map, floor plan, or building plan. In thedescription contained herein, the use of the term “location” maycomprise any of these variants unless indicated otherwise. Whencomputing the location of a UE, it is common to solve for local X, Y,and possibly Z coordinates and then, if needed, convert the localcoordinates into absolute ones (e.g., for latitude, longitude, andaltitude above or below mean sea level).

As noted, depending on desired functionality, the WAN 140 may compriseany of a variety of wireless and/or wireline communication networks. TheWAN 140 can, for example, comprise any combination of public and/orprivate networks, local and/or wide-area networks, and the like.Furthermore, the WAN 140 may utilize one or more wired and/or wirelesscommunication technologies. In some embodiments, the WAN 140 maycomprise a cellular or other mobile network, a WLAN, a WirelessWide-Area Network (WWAN), and/or the Internet, for example. Particularexamples of a WAN 140 include a 5G NR network, an LTE network, a Wi-FiWLAN, and the like. WAN 140 may also include more than one networkand/or network type.

Base stations 110 may comprise nodes in a cellular network, which mayallow the UE 120 to communicate wirelessly with other devices linked tothe WAN 140. The base stations 110 may have known locations, and maytherefore be used for positioning as described herein. As described infurther detail below, techniques are not necessarily limited to fixedbase stations (i.e., base stations having a fixed position), but mayalso include mobile base stations and even other UEs 120. For 5G NR, thebase stations 110 may comprise a next-generation Node B (gNB). A WAN 140comprising additional or alternative RATs may include base stations 110comprising a node B, an Evolved Node B (eNodeB or eNB), a basetransceiver station (BTS), a radio base station (RBS), a Next-GenerationeNB (ng-eNB), a Wi-Fi access point (AP), and/or a BT AP. Thus, UE 120can send and receive information with network-connected devices, such aslocation server 130, by accessing the WAN 140. And, as noted, the UE 120may access the WAN 140 via a base station 110. Base stations 110 and/orbase station antennas may be referred to as Transmission ReceptionPoints (TRPs).

The location server 130 may comprise a server and/or other computingdevice configured to determine an estimated location of UE 120 and/orprovide data (e.g., assistance data) to UE 120 to facilitate thelocation determination. According to some embodiments, location server130 may comprise an SUPL Location Platform (SLP), which may support theSUPL user plane (UP) location solution defined by the Open MobileAlliance (OMA) and may support location services for UE 120 based onsubscription information for UE 120 stored in location server 130. Thelocation server 130 may also comprise an Enhanced Serving MobileLocation Center (E-SMLC) that supports location of UE 120 using acontrol plane (CP) location solution for LTE radio access by UE 120. Thelocation server 130 may further comprise a Location Management Function(LMF) that supports location of UE 120 using a CP location solution for5G NR radio access by UE 120. In a CP location solution, signaling tocontrol and manage the location of UE 120 may be exchanged betweenelements of WAN 140 and with UE 120 using existing network interfacesand protocols and as signaling from the perspective of WAN 140. In a UPlocation solution, signaling to control and manage the location of UE120 may be exchanged between location server 130 and UE 120 as data(e.g., data transported using the Internet Protocol (IP) and/orTransmission Control Protocol (TCP)) from the perspective of WAN 140.

It can be further noted that, in some embodiments of a terrestrialpositioning system 100, the location server 130 may be executed byand/or incorporated into the UE 120 itself. That is, in the embodimentsdescribed herein, the functionality of the location server 130 may beperformed by the UE 120. In such instances, communication between the UEand location server may therefore occur between hardware and/or softwarecomponents of the UE 120. Similarly, the functions of the locationserver 130 described herein may be performed by a base station 110 orother device communicatively coupled to the terrestrial positioningsystem 100.

Additionally, positioning of the UE 120 can be “UE-based” or“network-based.” UE-based positioning comprises the UE 120 determiningits own location, which may be facilitated by information provided tothe UE 120 by the network (e.g., the location server 130 and/or basestations 110). Network-based positioning comprises the network (e.g.,the location server 130) determining the location of the UE, which maybe facilitated by information provided to the network by the UE 120. Thetechniques for RTT-based positioning provided herein may apply to eitherUE-based or network-based positioning. For example, for UE-basedpositioning, RTT measurements may be initiated by and/or communicated tothe UE 120, which, if provided the location of the base stations 110from which RTT measurements were taken, can determine its own location.For network-based positioning, RTT measurements may be initiated byand/or communicated to one or more base stations 110, which may send themeasurements to the location server 130, which can then determine thelocation of the UE 120.

The terrestrial positioning system 100 can determine the location of theUE 120 by exploiting both downlink (DL) information transmitted by basestations 110 and uplink (UL) information transmitted by the UE 120. Asexplained in more detail below, certain positioning methods can use RTTto determine the location of the UE 120 by determining one or moredistances 150 from base stations 110, then using multilateration orsimilar algorithms to determine the position of the UE 120. Inmultilateration, for example, distances 150-1, 150-2, and 150-3 tracerespective circles 160-1, 160-2, and 160-3 (only portions of which areshown in FIG. 1), and the location of the UE 120 may be determined asthe intersection of these circles 160. Alternative positioning methodsmay use a combination of distance information from one or more RTTmeasurements with angle information (e.g., AoA, AoD). An illustration ofhow distance can be determined using RTT is shown in FIG. 2.

FIG. 2 is a timing diagram illustrating the basic steps of an RTTmeasurement, with which a position of a UE 120 can be determined, andwhich may be utilized in the embodiments provided herein, as describedin more detail below. Here, an initiating device transmits a firstReference Signal (RS) 210 at a first time, T₁, which propagates to aresponding device. At a second time, T₂, the first RS 210 arrives at theresponding device. The Over-The-Air (OTA) delay (i.e., the propagationtime it takes for the first RS 210 to travel from the initiating deviceto the responding device) is T_(prop). The responding device thentransmits a second RS 220 at a third time, T₃. Finally, the second RS220 is received and measured by the initiating device at a fourth time,T₄. As with the first RS 210, the OTA delay of the second RS 220 isT_(prop).

Here, which devices comprise the initiating device and responding devicemay vary, depending on desired functionality. That is, in someinstances, the UE 120 may be the initiating device, and a base station110 may be the responding device. In other instances, the base station110 may be the initiating device, and the UE 120 may be the respondingdevice. Again, this may depend on whether the terrestrial positioningsystem 100 is performing UE-based positioning or network-basedpositioning. Additionally, as indicated in embodiments provided hereinbelow, there may be instances in which RTT measurements are takenbetween two different UEs. Thus, the initiating device may be a firstUE, and the responding device may be a second UE.

The RTT measurement shown in FIG. 2 may be used to determine a distance,d, between the initiating and responding devices. This can be determinedusing the following equation:

$\begin{matrix}{\frac{2d}{c} = {{\left( {T_{4} - T_{1}} \right) - \left( {T_{3} - T_{2}} \right)} = {\left( {T_{4} - T_{1}} \right) + {\left( {T_{2} - T_{3}} \right).}}}} & (1)\end{matrix}$

(As will be appreciated, distance, d, divided by the speed of RFpropagation, c, equals the propagation delay, T_(prop).) Thus, a precisedetermination of the distance between the initiating device andresponding device can be made.

The precision with which times T₁, T₂, T₃, and T₄ are measured, however,can be a limiting factor to the precision of the distance determinationmade by the RTT measurement. The accuracy of the determination of thetotal time between T₂ and T₃, known as the “Rx-Tx time offset,” caninfluence the precision of the distance determination. And with 5G NR'spromise of increased capabilities, it is important that these times aremeasured accurately. This can be especially true for low-tier UEs, whichhave a reduced operating bandwidth compared with premium UEs.

As used herein, the term “low-tier UE” or “low-tier device” refers to awireless device (UE) having a relatively low operating bandwidth, ascompared with a “premium UE” or “premium device,” which has a relativelyhigh operating bandwidth. Low-tier UEs may also be called“reduced-capability” UEs. Examples of low-tier UEs can include wearabledevices (e.g., smart watches), relaxed/narrowband IoT devices, low-endmobile phones, and the like. The current operating bandwidth of thesedevices is roughly 5-20 megahertz (MHz), although some low-tier UEs mayhave a higher or lower operating bandwidth. Examples of premium UEs maycomprise high-end mobile phones (e.g., smart phones), tablets, vehicles,and the like. Premium UEs currently operate at a bandwidth of 100 MHz ormore. Generally speaking, low-tier UEs have a relatively lower bandwidth(e.g., less than 100 MHz), lower processing capabilities, and/or lowerpower budgets than premium UEs. Importantly, while the group delay ofpremium UEs is often accurately determined (e.g., using proprietarycalibration techniques), it may be more difficult to determine the groupdelay of low-tier UEs. This can impact the accuracy of RTT measurements.

FIG. 3 is a timing diagram illustrating how group delay can impact theaccuracy of RTT measurements. Group delay in this context refers to thetime it takes an outgoing (TX) signal to travel from baseband processingcircuitry (“BB” in FIG. 3) to the antenna (“Ant”) of a device, or thetime it takes an incoming (RX) signal to travel from the antenna to thebaseband processing circuitry. (In a typical UE design, there may be oneor more analog components between the baseband processing circuitry andthe antenna.) As can be seen in FIG. 3, initiating device and respondingdevice each have a respective total group delay of Δ_(RX)+Δ_(TX) (whichmay be different for each device) that can impact the RTT measurement.For example, Rx-Tx time offset (the total time between the respondingdevice's receipt of the first RS 210 and transmission of the second RS220) is not simply T₃−T₂, but T₃−T₂ plus the group delay (Δ_(RX)+Δ_(TX))of the responding device.

The impact of group delay can be significant. For example, delay of asingle nanosecond can result in an error of two feet, resulting inlimited precision of the determined location of the UE. This, in turn,can limit the number of applications for which location determinationcan be used. And, as noted, although the group delay for premium UEs isoften determinable using proprietary means, the group delay for low-tierUEs is often not determinable using similar techniques. Moreover,because of the lower operating bandwidth of low-tier UEs, it may resultin lower accuracy for calibration. (A 100 MHz premium UE would have aresolution of 10 nanoseconds (ns), whereas a 20 MHz low-tier UE wouldhave a resolution of 50 ns.) Further complicating this issue is the factthat group delay can vary over time (e.g., it may vary across differentoperating temperatures), and therefore may not be determined by themanufacturer.

Embodiments provided herein solve these and other issues by providingtechniques for calibrating low-tier UEs to accurately account for groupdelay by leveraging the relatively high accuracy of RTT positioning forpremium UEs. This can enable online/in-field group delay calibration oflow-tier UEs, allowing for low-tier UEs to be calibrated when needed.Depending on desired functionality, different techniques for calibrationmay be used. When properly calibrated, a low-tier UE can provide anaccurate Rx-Tx time offset to account for group delay.

FIG. 4 is a diagram of a first technique for group delay calibration ofa low-tier UE, according to an embodiment. Here, the technique involvesusing a base station 110. In short, according to this technique, where alow-tier UE 410 is located near a premium UE 420, a first RTTmeasurement (RTT_1) is taken between the base station 110 and thelow-tier UE 410, a second RTT measurement (RTT_2) is taken between thebase station 110 and the premium UE 420, and then the two RTTmeasurements (RTT_1 and RTT_2) are compared to determine the group delayof the low-tier UE 410. (Because RTT_1 and RTT_2 should be approximatelythe same, the difference, therefore, can be attributed to the groupdelay of the low-tier UE 410.)

The effectiveness of this technique can depend on the co-location of thelow-tier UE 410 and premium UE 420. That is, to accurately determine thegroup delay of the low-tier UE 410, the low-tier UE 410 and premium UE420 should be substantially the same distance from the base station 110,such that the two RTT measurements should be substantially the same.

Any variety of techniques may be employed for choosing the premium UE420 to use in this technique. In many instances, for example, thelow-tier UE 410 may already be in communication with the premium UE 420(e.g., via direct communications, such as “sidelink” in LTE and NRstandards). A simple example of this would be the low-tier UE 410comprising a smart watch worn by a user who was also carrying a premiumUE 420 comprising a mobile phone. Some embodiments may enable a user toselect a premium UE 420 to use for calibration. This can includeenabling the user of the low-tier UE 410 to select from a list ofpremium UEs 420 in the approximate area of the low-tier UE 410, asdetermined by the terrestrial positioning system 100. Additionally oralternatively, the low-tier UE 410 may conduct a search for nearbypremium UEs 420 (e.g., using RF signaling to conduct a scan of availablepremium UEs 420). Other embodiments may do this automatically (e.g.,based on a premium UE 420 determined to be the closest to the low-tierUE 410 from among a plurality of premium UEs 420, or a premium UE 420being within a threshold distance from the low-tier UE 410, asdetermined by the terrestrial positioning system 100).

Some embodiments may leverage AoA capabilities of the base station 110to help determine a premium UE 420 to use for calibration. For example,a 5G NR base station 110 (e.g., a gNB) may be capable of performing AoAmeasurements to determine which premium UEs 420 are near the low-tier UE410. A premium UE 420 may then be selected if the AoA difference 430(e.g., the difference between the AoA of the premium UE 420 and the AoAof the low-tier UE 410, from the perspective of the base station 110) iswithin a certain threshold and/or the premium UE 420 has the smallestAoA difference 430 from a plurality of candidate premium UEs 420.Additionally or alternatively, if the AoA difference 430 is still abovea threshold minimum, the terrestrial positioning system 100 may conducttriangulation and/or another form of location determination of thepremium UE 420, to accommodate this offset in the location of thepremium UE 420 and the low-tier UE 410. This offset can then beaccounted for when conducting the two RTT measurements, to help ensurethe accuracy of the group delay determination for the low-tier UE 410.

The initiation of the RTT measurements and/or the determination of thegroup delay for the low-tier UE 410 may be executed a variety of ways,depending on desired functionality. In some instances, for example(e.g., for network-based positioning), the base station 110 may initiatethe RTT measurements and compare the RTT measurements to determine thegroup delay. In some embodiments, the base station 110 may furtherprovide the determined group delay to the low-tier UE 410 for future use(e.g., during a window of time in which the determined group delay maybe considered valid). In some instances, the low-tier UE 410 mayinitiate the first RTT measurement (RTT_1). In such instances, thesecond RTT measurement (RTT_2) may be initiated by the base station 110(e.g., in response to taking the first RTT measurement) or premium UE420 (e.g., in response to direct or indirect communications from thelow-tier UE 410), then provided to the low-tier UE 410 by the basestation 110 or premium UE 420 for determination of the group delay.(Once the low-tier UE 410 determines its group delay, it can, forexample, then perform UE-based positioning.) According to someembodiments, the group delay may be reported back to the terrestrialpositioning system 100, which may then account for the group delay insubsequent network-based positioning of the low-tier UE 410. (In someembodiments, the group delay of the low-tier UE 410 may be determined byor communicated to the premium UE 420, which can then relay the groupdelay to the base station 110. This way of communicating the group delayof the low-tier UE 410 may be preferable in certain instances, giventhat the premium UE 420 likely has a higher power budget than thelow-tier UE 410.)

FIG. 5 is a diagram of a second technique for group delay calibration ofa low-tier UE, according to an embodiment, which may be used in additionor as an alternative to the first technique illustrated in FIG. 4 anddescribed above. Unlike the first technique, the technique illustratedin FIG. 5 does not involve a base station 110, but instead takes an RTTmeasurement at a known distance 510 to be able to determine the groupdelay of the low-tier UE 410. That is, according to this technique, anRTT measurement is made by the premium UE 420 and low-tier UE 410 whilethe premium UE 420 and low-tier UE 410 are situated at a known distance510 from each other. Because they are at a known distance 510 (andbecause the group delay of the premium UE 420 is known and accountedfor), any difference between the known distance 510 and distance derivedfrom the RTT measurement may be attributed to an inaccuracy in thedetermination of the group delay for the low-tier UE 410. The groupdelay of the low-tier UE 410 may then be recalibrated to ensure accurateRTT measurements. According to some embodiments, the group delay may bereported back to the terrestrial positioning system 100, which may thenaccount for the group delay in subsequent network-based positioning ofthe low-tier UE 410.

The technique illustrated in FIG. 5 may be conducted in any of a varietyof ways. According to some embodiments, a user of the low-tier UE 410may be guided through a process for making this calibration using, forexample, a user interface of the low-tier UE 410 and/or premium UE 420.Some embodiments may allow the user to confirm that the premium UE 420and low-tier UE 410 have been accurately placed via user input (e.g.,the press of a button on a touchscreen display of the premium UE 420 orlow-tier UE 410). In some embodiments, the user may be able to locatethe premium UE 420 and low-tier UE 410 at a desired distance, thenprovide the distance (e.g., the known distance 510) via a user input.Additionally or alternatively, the user interface of the low-tier UE 410and/or premium UE 420 may tell the user the distance at which to locatethe premium UE 420 and low-tier UE 410. (In some embodiments, the usermay then confirm that the UEs have been placed at the appropriatedistance.)

According to some embodiments, the RTT measurements between the premiumUE 420 and low-tier UE 410 may be made, for example, using protocols forUE-based positioning based on communication with other UEs, as providedin 5G NR. In some embodiments, for example, this may involve utilizing aChannel State Information Reference Signal (CSI-RS), which can betransmitted for Channel Quality Information (CQI) purposes in sidelinkfor the purpose of positioning. In this case both UEs may transmit aCSI-RS inside a Physical Sidelink Shared Channel (PSSCH), and thereceiving UE can measure the corresponding group delay.

FIG. 6 is a flow diagram of a method 600 of determining the group delayof a first mobile device (e.g., a low-tier UE), according to anembodiment utilizing a base station. The method 600, therefore, may beseen as a method of performing the calibration previously described withregard to FIG. 4. As noted in the embodiments previously described, theinitiation of RTT measurements and/or determination of delay for thefirst mobile device may be performed by one or more different devices.As such, the functionality shown in the blocks of FIG. 6 may beperformed by the first mobile device, a second mobile device (e.g., apremium UE), and/or the base station. Further, means for performing thefunctionality of method 600 may include hardware and/or softwarecomponents of a mobile device (e.g., UE illustrated in FIG. 8), and/orhardware and/or software components of the base station 110 illustratedin FIG. 9, both of which are described in more detail below.Additionally, it can be noted that, as with other figures appendedhereto, FIG. 6 is provided as a non-limiting example. Other embodimentsmay vary, depending on desired functionality. For example, thefunctional blocks illustrated in method 600 may be combined, separated,or rearranged to accommodate different embodiments.

At block 610, the functionality comprises obtaining a first RTTmeasurement between the first mobile device and a base station. Asnoted, the RTT measurement itself may be initiated by the base stationor first mobile device, depending on desired functionality. Moreover, insome embodiments, the measurement may be obtained by a device other thanthe device initiating the RTT measurement (e.g., the first mobile devicemay take the measurement and send it to the base station, or the basestation may take the measurement and send it to the first mobiledevice). Means for performing the functionality at block 610 maycomprise software and/or hardware components of a UE, such as the bus805, processing unit(s) 810, DSP 820, wireless communication interface830, memory 860, and/or other components of the UE 120 illustrated inFIG. 8 and described in more detail below. Additionally oralternatively, means for performing the functionality at block 610 maycomprise software and/or hardware components of a base station, such asthe bus 905, processing unit(s) 910, DSP 920, wireless communicationinterface 930, memory 960, and/or other components of the base station110 illustrated in FIG. 9 and described in more detail below.

The functionality at block 620 comprises identifying a second mobiledevice within a threshold distance of the first mobile device, whereinthe second mobile device has a higher bandwidth than the first mobiledevice. In some embodiments, the first mobile device comprises alow-tier UE having a bandwidth of less than 100 MHz, and the secondmobile device comprises a premium UE having a bandwidth of 100 MHz ormore.

As indicated in the previously described embodiments, identifying thesecond mobile device may comprise any of a variety of techniques. Insome embodiments, identifying the second mobile device comprisesdetermining that a difference between a first AoA measurement by thebase station of the first mobile device and a second AoA measurement bythe base station of the second mobile device is within a thresholdvalue. Additionally or alternatively, the first mobile device mayperform a scan and allow a user to select a desired second mobile devicewith which to perform calibration. As such, according to someembodiments, identifying the second mobile device may compriseperforming a scan by the first mobile device. Moreover, identifying mayfurther comprise receiving a user selection of a premium device from alist of a plurality of devices detected from the scan.

Means for performing the functionality at block 620 may comprisesoftware and/or hardware components of a UE, such as the bus 805,processing unit(s) 810, DSP 820, wireless communication interface 830,memory 860, and/or other components of the UE 120 illustrated in FIG. 8and described in more detail below. Additionally or alternatively, meansfor performing the functionality at block 620 may comprise softwareand/or hardware components of a base station, such as the bus 905,processing unit(s) 910, DSP 920, wireless communication interface 930,memory 960, and/or other components of the base station 110 illustratedin FIG. 9 and described in more detail below.

At block 630, the functionality comprises obtaining a second RTTmeasurement between the second mobile device and the base station.Again, the RTT measurement itself may be initiated by the base stationor second mobile device, depending on desired functionality. Further, insome embodiments, the RTT measurement may be sent from one device toanother (e.g., from UE to base station or vice versa). Means forperforming the functionality at block 630 may comprise software and/orhardware components of a UE, such as the bus 805, processing unit(s)810, DSP 820, wireless communication interface 830, memory 860, and/orother components of the UE 120 illustrated in FIG. 8 and described inmore detail below. Additionally or alternatively, means for performingthe functionality at block 630 may comprise software and/or hardwarecomponents of a base station, such as the bus 905, processing unit(s)910, DSP 920, wireless communication interface 930, memory 960, and/orother components of the base station 110 illustrated in FIG. 9 anddescribed in more detail below.

At block 640, the functionality comprises determining a group delay ofthe first mobile device based on a difference between the first RTTmeasurement and the second RTT measurement. As previously noted, becausethe group delay of the second mobile device may be known and accountedfor, this allows for determination of the group delay of the firstmobile device. And again, the base station, first mobile device, orsecond mobile device may make this determination of the group delayusing the obtained first and second RTT measurements. In instances inwhich the first mobile device determines the group delay, the firstmobile device may further send information indicative of the determinedgroup delay to the base station (e.g., for use in network-basedpositioning of the first mobile device). In some embodiments, the firstmobile device can be calibrated to account for group delay. And thus,the information indicative of the determined group delay can include,for example, the Rx-Tx time offset, accounting for the determined groupdelay. To preserve power, the first mobile device may send thedetermined group delay to the second mobile device, and the secondmobile device may send the information indicative of the determinedgroup delay to the base station. In instances in which the second mobiledevice determines the group delay, the second mobile device may furthersend the information indicative of the determined group delay to thebase station and/or first mobile device. In instances in which the basestation determines the group delay, the base station may send theinformation indicative of the group delay to the first mobile device(e.g., for use in UE-based positioning of the first mobile device).

Means for performing the functionality at block 640 may comprisesoftware and/or hardware components of a UE, such as the bus 805,processing unit(s) 810, DSP 820, wireless communication interface 830,memory 860, and/or other components of the UE 120 illustrated in FIG. 8and described in more detail below. Additionally or alternatively, meansfor performing the functionality at block 640 may comprise softwareand/or hardware components of a base station, such as the bus 905,processing unit(s) 910, DSP 920, wireless communication interface 930,memory 960, and/or other components of the base station 110 illustratedin FIG. 9 and described in more detail below.

FIG. 7 is a flow diagram of a method 700 of determining the group delayof a first mobile device (e.g., a low-tier UE), according to anembodiment that uses direct communications with a second mobile device(e.g., a premium UE). The method 700, therefore, may be seen as a methodof performing the calibration previously described with regard to FIG.5. As noted in the embodiments previously described, the initiation ofRTT measurements and/or determination of delay for the first mobiledevice may be performed by either the first or second mobile device. Assuch, means for performing the functionality of method 700 may includehardware and/or software components of the UE illustrated in FIG. 8.Additionally, it can be noted that, as with figures appended hereto,FIG. 7 is provided as a non-limiting example. Other embodiments mayvary, depending on desired functionality. For example, the functionalblocks illustrated in method 700 may be combined, separated, orrearranged to accommodate different embodiments.

The functionality at block 710 comprises obtaining informationindicative of a known distance between the first mobile device and thesecond mobile device, wherein the second mobile device has a higherbandwidth than the first mobile device. In some embodiments, the firstmobile device comprises a low-tier UE having a bandwidth of less than100 MHz, and the second mobile device comprises a premium-tier UE havinga bandwidth of 100 MHz or more. Again, according to embodiments, thisinformation may be obtained using a guided process in which the firstand/or second mobile device guides a user into positioning each mobiledevice such that there is a known distance between the first mobiledevice and the second mobile device. Thus, according to embodiments,obtaining information indicative of the known distance between the firstmobile device and the second mobile device may comprise receiving userinput of a distance between the first mobile device on the second mobiledevice, receiving user input verifying that the first mobile device andsecond mobile device have been placed at a requested distance, or thelike. Means for performing the functionality at block 710 may comprisesoftware and/or hardware components of a UE, such as the bus 805,processing unit(s) 810, DSP 820, input device(s) 870, output device(s)815, wireless communication interface 830, memory 860, and/or othercomponents of the UE 120 illustrated in FIG. 8 and described in moredetail below.

At block 720, the functionality comprises obtaining an RTT measurementbetween the first mobile device and the second mobile device. As notedin the embodiments above, this may involve utilizing a sidelink channel(e.g., utilizing CSI-RS confined within a PSSCH transmission).Additionally or alternatively, the RTT measurement may be taken inresponse to user input. More specifically, the RTT measurement may beperformed in response to receiving a user input comprising informationconfirming that the first mobile device and the second mobile device arelocated the known distance apart. (Depending on desired functionality,the first mobile device may be the initiating device and the secondmobile device may be the responding mobile device, or vice versa. Ineither case, the RTT measurement may be provided to the devicedetermining the group delay of the first mobile device.) Means forperforming the functionality at block 720 may comprise software and/orhardware components of a UE, such as the bus 805, processing unit(s)810, DSP 820, wireless communication interface 830, memory 860, and/orother components of the UE 120 illustrated in FIG. 8 and described inmore detail below.

The functionality at block 730 comprises determining a group delay ofthe first mobile device based on a difference between the known distanceand a distance determined by the RTT measurement. A difference betweenthe known distance and a distance determined using the RTT measurementmay be indicative of the group delay (Δ_(RX)+Δ_(TX)) of the first mobiledevice (or an error in a current group delay estimate for the firstmobile device). The first mobile device can then be calibratedaccordingly to account for the determined group delay. For example, if adistance derived from the RTT measurement is two feet longer than theknown distance, the group delay is approximately 1 ns. Alternatively, ifa current group delay estimate was accounted for the RTT measurement,this would mean the current group delay estimate is 1 ns shorter than itshould be, and the group delay estimate can be adjusted accordingly.Again, this determination may be made by either the first mobile deviceor the second mobile device, and information indicative of thisdetermination may be reported to the network (e.g., via a base station)for subsequent network-based positioning using RTT measurements of thefirst mobile device.

Means for performing the functionality at block 730 may comprisesoftware and/or hardware components of a UE, such as the bus 805,processing unit(s) 810, DSP 820, wireless communication interface 830,memory 860, and/or other components of the UE 120 illustrated in FIG. 8.

FIG. 8 is a block diagram of an embodiment of a UE 120, which can beutilized as described in the embodiments described herein and inassociation with FIGS. 1-7. Specifically, the UE 120 of FIG. 8 maycorrespond to any type of UE (e.g., low-tier and/or premium) discussedin the embodiments above, including the UE 120 of FIG. 1 and/or eitheror both of the low-tier UE 410 and premium UE 420 of FIGS. 4 and 5. Itshould be noted that FIG. 8 is meant only to provide a generalizedillustration of various components of UE 120, any or all of which may beutilized as appropriate. In other words, because UEs can vary widely infunctionality, they may include only a portion of the components shownin FIG. 8. A premium UE, for example, may include more of the componentsshown in FIG. 8 than does a low-tier UE. It can be noted that, in someinstances, components illustrated by FIG. 8 can be localized to a singlephysical device and/or distributed among various networked devices,which may be disposed at different physical locations.

The UE 120 is shown comprising hardware elements that can beelectrically coupled via a bus 805 (or may otherwise be in communicationas appropriate). The hardware elements may include a processing unit(s)810 which may comprise, without limitation, one or more general-purposeprocessors, one or more special-purpose processors (such as digitalsignal processing (DSP) chips, graphics acceleration processors,application-specific integrated circuits (ASICs), and/or the like),and/or other processing structure or means, which can be configured toperform one or more of the methods described herein. As shown in FIG. 8,some embodiments may have a separate DSP 820, depending on desiredfunctionality. The UE 120 also may comprise one or more input devices870, which may comprise, without limitation, one or more touchscreens,touchpads, microphones, buttons, dials, switches, and/or the like; andone or more output devices 815, which may comprise, without limitation,one or more displays, light-emitting diodes (LEDs), speakers, and/or thelike.

The UE 120 might also include a wireless communication interface 830,which may comprise, without limitation, a modem, a network card, aninfrared communication device, a wireless communication device, and/or achipset (such as a BT device, an IEEE 802.11 device, an IEEE 802.15.4device, a Wi-Fi device, a WiMAX™ device, cellular communicationfacilities, etc.), and/or the like, which may enable the UE 120 tocommunicate via the networks (e.g., via a base station) described hereinwith regard to FIG. 1. The wireless communication interface 830 maypermit data to be communicated with a network, base stations (e.g.,eNBs, ng-eNBs, and/or gNBs), and/or other TRPs, network components,computer systems, and/or any other electronic devices described herein.The communication can be carried out via one or more wirelesscommunication antenna(s) 832 that send and/or receive wireless signals834.

Depending on desired functionality, the wireless communication interface830 may comprise separate base stations to communicate with basestations (e.g., eNBs, ng-eNBs, and/or gNBs) and other terrestrial basestations, such as wireless devices and APs. The UE 120 may communicatewith different data networks that may comprise various network types.For example, a WWAN may be a CDMA network, a Time Division MultipleAccess (TDMA) network, a Frequency Division Multiple Access (FDMA)network, an Orthogonal Frequency Division Multiple Access (OFDMA)network, a Single-Carrier Frequency Division Multiple Access (SC-FDMA)network, a WiMax (IEEE 802.16), and so on. A CDMA network may implementone or more RATs, such as cdma2000, WCDMA, and so on. Cdma2000 includesIS-95, IS-2000, and/or IS-856 standards. A TDMA network may implementGSM, Digital Advanced Mobile Phone System (D-AMPS), or some other RAT.An OFDMA network may employ LTE, LTE Advanced, NR, and so on. 5G, LTE,LTE Advanced, NR, GSM, and WCDMA are described in documents from 3GPP.Cdma2000 is described in documents from a consortium named “3rdGeneration Partnership Project 2” (3GPP2). 3GPP and 3GPP2 documents arepublicly available. A WLAN may also be an IEEE 802.11x network, and awireless personal area network (WPAN) may be a BT network, an IEEE802.15x, or some other type of network. The techniques described hereinmay also be used for any combination of WWAN, WLAN, and/or WPAN.

The UE 120 can further include sensor(s) 840. Such sensors may comprise,without limitation, one or more inertial sensors (e.g.,accelerometer(s), gyroscope(s), and or other Inertial Measurement Units(IMUs)), camera(s), magnetometer(s), compass, altimeter(s),microphone(s), proximity sensor(s), light sensor(s), barometer, and thelike, some of which may be used to complement and/or facilitate thefunctionality described herein.

Embodiments of the UE 120 may also include a Global Navigation SatelliteSystem (GNSS) receiver 880 capable of receiving signals 884 from one ormore GNSS satellites using an GNSS antenna 882 (which may be combined insome implementations with antenna(s) 832). Such positioning can beutilized to complement and/or incorporate the techniques describedherein. The GNSS receiver 880 can extract a position of the UE 120,using conventional techniques, from GNSS satellites of a GNSS system,such as Global Positioning System (GPS), Galileo, GLObal NAvigationSatellite System (GLONASS), Compass, Quasi-Zenith Satellite System(QZSS) over Japan, Indian Regional Navigation Satellite System (IRNSS)over India, BeiDou Navigation Satellite System (BDS) over China, and/orthe like. Moreover, the GNSS receiver 880 can use various augmentationsystems (e.g., a Satellite-Based Augmentation System (SBAS)) that may beassociated with or otherwise enabled for use with one or more globaland/or regional navigation satellite systems. By way of example, but notlimitation, an SBAS may include an augmentation system(s) that providesintegrity information, differential corrections, and so on, such as WideArea Augmentation System (WAAS), European Geostationary NavigationOverlay Service (EGNOS), Multi-functional Satellite Augmentation System(MSAS), GPS-Aided GEO-Augmented Navigation or GPS and GEO-AugmentedNavigation system (GAGAN), and/or the like. Thus, as used herein, a GNSSmay include any combination of one or more global and/or regionalnavigation satellite systems and/or augmentation systems, and GNSSsignals may include GNSS, GNSS-like, and/or other signals associatedwith such one or more GNSS.

The UE 120 may further include and/or be in communication with a memory860. The memory 860 may comprise, without limitation, local and/ornetwork-accessible storage, a disk drive, a drive array, an opticalstorage device, a solid-state storage device (such as a random accessmemory (RAM) and/or a read-only memory (ROM)), which can beprogrammable, flash-updateable, and/or the like. Such storage devicesmay be configured to implement any appropriate data stores, including,without limitation, various file systems, database structures, and/orthe like.

The memory 860 of the UE 120 also can comprise software elements (notshown), including an operating system, device drivers, executablelibraries, and/or other code, such as one or more application programs,which may comprise computer programs provided by various embodiments,and/or may be designed to implement methods and/or configure systems,provided by other embodiments, as described herein. Merely by way ofexample, one or more procedures described with respect to thefunctionality discussed above might be implemented as code and/orinstructions executable by the UE 120 (e.g., using processing unit(s)810). In an aspect, then, such code and/or instructions can be used toconfigure and/or adapt a general-purpose computer (or other device) toperform one or more operations in accordance with the described methods.

FIG. 9 illustrates an embodiment of a base station 110, which can beutilized as described herein above (e.g., in association with FIGS.1-7). It should be noted that FIG. 9 is meant only to provide ageneralized illustration of various components, any or all of which maybe utilized as appropriate. In some embodiments, the base station 110may correspond to a gNB, an ng-eNB, and/or an eNB.

The base station 110 is shown comprising hardware elements that can beelectrically coupled via a bus 905 (or may otherwise be in communicationas appropriate). The hardware elements may include a processing unit(s)910, which can include, without limitation, one or more general-purposeprocessors, one or more special-purpose processors (such as DSP chips,graphics acceleration processors, ASICs, and/or the like), and/or otherprocessing structure or means. As shown in FIG. 9, some embodiments mayhave a separate DSP 920, depending on desired functionality. Locationdetermination and/or other determinations based on wirelesscommunication may be provided in the processing unit(s) 910 and/orwireless communication interface 930 (discussed below), according tosome embodiments. The base station 110 also can include one or moreinput devices, which can include, without limitation, a keyboard,display, mouse, microphone, button(s), dial(s), switch(es), and/or thelike; and one or more output devices, which can include, withoutlimitation, a display, LED, speakers, and/or the like.

The base station 110 might also include a wireless communicationinterface 930, which may comprise, without limitation, a modem, anetwork card, an infrared communication device, a wireless communicationdevice, and/or a chipset (such as a BT device, an IEEE 802.11 device, anIEEE 802.15.4 device, a Wi-Fi device, a WiMAX device, cellularcommunication facilities), and/or the like, which may enable the basestation 110 to communicate as described herein. The wirelesscommunication interface 930 may permit data and signaling to becommunicated (e.g., transmitted and received) with UEs, other basestations (e.g., eNBs, gNBs, and ng-eNBs), and/or other TRPs, or networkcomponents, computer systems, and/or any other electronic devicesdescribed herein. The communication can be carried out via one or morewireless communication antenna(s) 932 that send and/or receive wirelesssignals 934.

The base station 110 may also include a network interface 980, which caninclude support of wireline communication technologies. The networkinterface 980 may include a modem, network card, chipset, and/or thelike. The network interface 980 may include one or more input and/oroutput communication interfaces to permit data to be exchanged with anetwork, communication network servers, computer systems, and/or anyother electronic devices described herein.

In many embodiments, the base station 110 may further comprise a memory960. The memory 960 can include, without limitation, local and/ornetwork-accessible storage, a disk drive, a drive array, an opticalstorage device, a solid-state storage device such as a RAM, and/or aROM, which can be programmable, flash-updateable, and/or the like. Suchstorage devices may be configured to implement any appropriate datastores, including, without limitation, various file systems, databasestructures, and/or the like.

The memory 960 of the base station 110 also may comprise softwareelements (not shown in FIG. 9), including an operating system, devicedrivers, executable libraries, and/or other code, such as one or moreapplication programs, which may comprise computer programs provided byvarious embodiments, and/or may be designed to implement methods and/orconfigure systems, provided by other embodiments, as described herein.Merely by way of example, one or more procedures described with respectto the method(s) discussed above may be implemented as code and/orinstructions in memory 960 that are executable by the base station 110(and/or processing unit(s) 910 or DSP 920 within base station 110). Inan aspect, then, such code and/or instructions can be used to configureand/or adapt a general-purpose computer (or other device) to perform oneor more operations in accordance with the described methods.

It will be apparent to those skilled in the art that substantialvariations may be made in accordance with specific requirements. Forexample, customized hardware might also be used, and/or particularelements might be implemented in hardware, software (including portablesoftware, such as applets), or both. Further, connection to othercomputing devices, such as network I/O devices, may be employed.

With reference to the appended figures, components that can includememory can include non-transitory machine-readable media. The terms“machine-readable medium” and “computer-readable medium,” as usedherein, refer to any storage medium that participates in providing datathat causes a machine to operate in a specific fashion. In embodimentsprovided hereinabove, various machine-readable media might be involvedin providing instructions/code to processing units and/or otherdevice(s) for execution. Additionally or alternatively, themachine-readable media might be used to store and/or carry suchinstructions/code. In many implementations, a computer-readable mediumis a physical and/or tangible storage medium. Such a medium may takemany forms, including, but not limited to, non-volatile media, volatilemedia, and transmission media. Common forms of computer-readable mediainclude, for example, magnetic and/or optical media, any other physicalmedium with patterns of holes, a RAM, a programmable ROM (PROM), anerasable PROM (EPROM), a FLASH-EPROM, any other memory chip orcartridge, a carrier wave as described hereinafter, or any other mediumfrom which a computer can read instructions and/or code.

The methods, systems, and devices discussed herein are examples. Variousembodiments may omit, substitute, or add various procedures orcomponents as appropriate. For instance, features described with respectto certain embodiments may be combined in various other embodiments.Different aspects and elements of the embodiments may be combined in asimilar manner. The various components of the figures provided hereincan be embodied in hardware and/or software. Also, technology evolves,and thus, many of the elements are examples that do not limit the scopeof the disclosure to those specific examples.

It has proven convenient at times, principally for reasons of commonusage, to refer to such signals as “bits,” “information,” “values,”“elements,” “symbols,” “characters,” “variables,” “terms,” “numbers,”“numerals,” or the like. It should be understood, however, that all ofthese or similar terms are to be associated with appropriate physicalquantities and are merely convenient labels. Unless specifically statedotherwise, as is apparent from the discussion above, it is appreciatedthat throughout this Specification, discussions utilizing terms such as“processing,” “computing,” “calculating,” “determining,” “ascertaining,”“identifying,” “associating,” “measuring,” “performing,” or the likerefer to actions or processes of a specific apparatus, such as aspecial-purpose computer or a similar special-purpose electroniccomputing device. In the context of this Specification, therefore, aspecial-purpose computer or a similar special-purpose electroniccomputing device is capable of manipulating or transforming signals,typically represented as physical, electronic, electrical, or magneticquantities within memories, registers, or other information storagedevices, transmission devices, or display devices of the special-purposecomputer or similar special-purpose electronic computing device.

Terms “and” and “or,” as used herein, may include a variety of meaningswhich also are expected to depend at least in part upon the context inwhich such terms are used. Typically, “or” if used to associate a list,such as A, B, or C, is intended to mean A, B, and C, here used in theinclusive sense, as well as A, B, or C, here used in the exclusivesense. In addition, the term “one or more,” as used herein, may be usedto describe any feature, structure, or characteristic in the singular ormay be used to describe some combination of features, structures, orcharacteristics. However, it should be noted that this is merely anillustrative example and claimed subject matter is not limited to thisexample. Furthermore, the term “at least one of” if used to associate alist, such as A, B, or C, can be interpreted to mean any combination ofA, B, and/or C, such as A, AB, AA, AAB, or AABBCCC.

Having described several embodiments, various modifications, alternativeconstructions, and equivalents may be used without departing from thespirit of the disclosure. For example, the above elements may merely bea component of a larger system, wherein other rules may take precedenceover or otherwise modify the application of the various embodiments.Also, a number of steps may be undertaken before, during, or after theabove elements are considered. Accordingly, the above description doesnot limit the scope of the disclosure.

What is claimed is:
 1. A method of determining a group delay of a firstmobile device, the method comprising: obtaining information indicativeof a known distance between the first mobile device and a second mobiledevice, wherein the second mobile device has a higher bandwidth than thefirst mobile device; obtaining a Round-Trip-Time (RTT) measurementbetween the first mobile device and the second mobile device; anddetermining a group delay of the first mobile device based on adifference between the known distance and a distance determined by theRTT measurement.
 2. The method of claim 1, wherein the first mobiledevice comprises a low-tier User Equipment (UE) having a bandwidth ofless than 100 MHz, and the second mobile device comprises a premium-tiermobile device having a bandwidth of 100 MHz or more.
 3. The method ofclaim 1, wherein the first mobile device determines the group delay. 4.The method of claim 1, wherein the second mobile device determines thegroup delay.
 5. The method of claim 1, wherein the RTT measurement isperformed in response to receiving a user input, wherein the user inputcomprises information confirming that the first mobile device and thesecond mobile device are located the known distance apart.
 6. A mobiledevice comprising: a transceiver; a memory; and one or more processingunits communicatively coupled with the transceiver and the memory andconfigured to: obtain information indicative of a known distance betweena first mobile device and a second mobile device, wherein the secondmobile device has a higher bandwidth than the first mobile device;obtain, using the transceiver, a Round-Trip-Time (RTT) measurementbetween the first mobile device and the second mobile device; anddetermine a group delay of the first mobile device based on a differencebetween the known distance and a distance determined by the RTTmeasurement.
 7. The mobile device of claim 6, wherein the mobile devicecomprises the first mobile device, which comprises a low-tier UserEquipment (UE) having a bandwidth of less than 100 MHz.
 8. The mobiledevice of claim 6, wherein the mobile device comprises the second mobiledevice, which comprises a premium-tier mobile device having a bandwidthof 100 MHz or more.
 9. The mobile device of claim 6, wherein the one ormore processing units are configured to obtain the RTT measurement inresponse to receiving a user input comprising information confirmingthat the first mobile device and the second mobile device are locatedthe known distance apart.
 10. A mobile device comprising: means forobtaining, at the mobile device, information indicative of a knowndistance between a first mobile device and a second mobile device,wherein the second mobile device has a higher bandwidth than the firstmobile device; means for obtaining, at the mobile device, aRound-Trip-Time (RTT) measurement between the first mobile device andthe second mobile device; and means for determining, at the mobiledevice, a group delay of the first mobile device based on a differencebetween the known distance and a distance determined by the RTTmeasurement.
 11. The mobile device of claim 10, wherein the mobiledevice comprises the first mobile device, which comprises a low-tierUser Equipment (UE) having a bandwidth of less than 100 MHz.
 12. Themobile device of claim 10, wherein the mobile device comprises thesecond mobile device, which comprises a premium-tier mobile devicehaving a bandwidth of 100 MHz or more.
 13. The mobile device of claim10, wherein the means for obtaining the RTT measurement are configuredto obtain the RTT measurement in response to receiving a user inputcomprising information confirming that the first mobile device and thesecond mobile device are located the known distance apart.
 14. Anon-transitory computer-readable medium storing instructions fordetermining a group delay of a mobile device, the instructionscomprising code for: obtaining information indicative of a knowndistance between a first mobile device and a second mobile device,wherein the second mobile device has a higher bandwidth than the firstmobile device; obtaining a Round-Trip-Time (RTT) measurement between thefirst mobile device and the second mobile device; and determining agroup delay of the first mobile device based on a difference between theknown distance and a distance determined by the RTT measurement.
 15. Thenon-transitory computer-readable medium of claim 14, wherein the mobiledevice comprises the first mobile device, which comprises a low-tierUser Equipment (UE) having a bandwidth of less than 100 MHz.
 16. Thenon-transitory computer-readable medium of claim 14, wherein the mobiledevice comprises the second mobile device, which comprises apremium-tier mobile device having a bandwidth of 100 MHz or more. 17.The non-transitory computer-readable medium of claim 14, wherein thecode for obtaining the RTT measurement comprises code for obtaining theRTT measurement in response to receiving a user input comprisinginformation confirming that the first mobile device and the secondmobile device are located the known distance apart.